Pope Francis leaves after celebrating a Mass in St. Peter's Basilica at the Vatican, Sunday, Oct. 25, 2015. Pope Francis declared Sunday that "Today is a time of mercy!" as he closed out a historic meeting of bishops that approved an important new direction in welcoming divorced and civilly remarried Catholics into the church. (AP Photo/Alessandra Tarantino)
(The Associated Press)

VATICAN CITY – Just days after closing a contentious meeting of bishops from around the world, Pope Francis is turning his attention to more domestic but equally contentious affairs.

Francis issued a stern warning Tuesday to Vatican bureaucrats to obey Vatican rules and laws as he goes about overhauling the Vatican bureaucracy — a sign that those charged with enacting the reforms perhaps need some reform themselves.

Francis penned an unusual letter to the Vatican secretary of state, Cardinal Pietro Parolin, asking him to remind Curia leaders that they must observe Vatican law about the structure and powers of the existing administration and follow existing rules on new hires, transfers and salary caps.

The target of Francis' letter appeared to be the new Secretariat for the Economy.